Patents by Inventor Lars Villemoes

Lars Villemoes has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10236010
    Abstract: In some embodiments, a pitch filter for filtering a preliminary audio signal generated from an audio bitstream is disclosed. The pitch filter has an operating mode selected from one of either: (i) an active mode where the preliminary audio signal is filtered using filtering information to obtain a filtered audio signal, and (ii) an inactive mode where the pitch filter is disabled. The preliminary audio signal is generated in an audio encoder or audio decoder having a coding mode selected from at least two distinct coding modes, and the pitch filter is capable of being selectively operated in either the active mode or the inactive mode while operating in the coding mode based on control information.
    Type: Grant
    Filed: October 24, 2017
    Date of Patent: March 19, 2019
    Assignee: Dolby International AB
    Inventors: Barbara Resch, Kristofer Kjörling, Lars Villemoes
  • Publication number: 20190081719
    Abstract: Systems and methods are described for concealing packet loss in a received audio stream. Candidate frequency lines may be identified within one or two previous frames of the audio stream. For two-frame concealment, gains may be calculated for each candidate frequency line between a first frame and a second frame, and candidate frequency lines may be selected based on the calculated gains. Different techniques may be used to select the candidate frequency lines, including a full-search method and a hybrid method based on selecting peaks from a pseudospectrum. Sub-band predictors may be selected from a database of predictor candidates based on the selected candidate frequency lines. Each predictor may be a function of frequency, and the selected predictors may be arranged as a matrix. The sub-band predictors may then be applied to corresponding blocks of the second frame to obtain sub-band coefficients used to reconstruct the lost frame.
    Type: Application
    Filed: September 10, 2018
    Publication date: March 14, 2019
    Applicants: Dolby Laboratories Licensing Corporation, Dolby International AB
    Inventors: Shen HUANG, Lars VILLEMOES
  • Publication number: 20190066707
    Abstract: The present invention proposes a new method for improving the performance of a real-valued filterbank based spectral envelope adjuster. By adaptively locking the gain values for adjacent channels dependent on the sign of the channels, as defined in the application, reduced aliasing is achieved. Furthermore, the grouping of the channels during gain-calculation, gives an improved energy estimate of the real valued subband signals in the filterbank.
    Type: Application
    Filed: October 29, 2018
    Publication date: February 28, 2019
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Kristofer KJOERLING, Lars VILLEMOES
  • Patent number: 10192565
    Abstract: The present invention relates to audio coding systems which make use of a harmonic transposition method for high frequency reconstruction (HFR). A system and a method for generating a high frequency component of a signal from a low frequency component of the signal is described. The system comprises an analysis filter bank providing a plurality of analysis subband signals of the low frequency component of the signal. It also comprises a non-linear processing unit to generate a synthesis subband signal with a synthesis frequency by modifying the phase of a first and a second of the plurality of analysis subband signals and by combining the phase-modified analysis subband signals. Finally, it comprises a synthesis filter bank for generating the high frequency component of the signal from the synthesis subband signal.
    Type: Grant
    Filed: September 20, 2017
    Date of Patent: January 29, 2019
    Assignee: Dolby International AB
    Inventors: Lars Villemoes, Per Hedelin
  • Patent number: 10192562
    Abstract: The invention provides an efficient implementation of cross-product enhanced high-frequency reconstruction (HFR), wherein a new component at frequency Q?+r?0 is generated on the basis of existing components at ? and ?+?0. The invention provides a block-based harmonic transposition, wherein a time block of complex subband samples is processed with a common phase modification. Superposition of several modified samples has the net effect of limiting undesirable intermodulation products, thereby enabling a coarser frequency resolution and/or lower degree of oversampling to be used. In one embodiment, the invention further includes a window function suitable for use with block-based cross-product enhanced HFR. A hardware embodiment of the invention may include an analysis filter bank, a subband processing unit configurable by control data and a synthesis filter bank.
    Type: Grant
    Filed: February 26, 2018
    Date of Patent: January 29, 2019
    Assignee: Dolby International AB
    Inventor: Lars Villemoes
  • Patent number: 10186280
    Abstract: The present invention relates to coding of audio signals, and in particular to high frequency reconstruction methods including a frequency domain harmonic transposer. A system and method for generating a high frequency component of a signal from a low frequency component of the signal is described.
    Type: Grant
    Filed: October 25, 2017
    Date of Patent: January 22, 2019
    Assignee: Dolby International AB
    Inventors: Lars Villemoes, Per Ekstrand
  • Publication number: 20190019528
    Abstract: The present document relates to audio source coding systems which make use of a harmonic transposition method for high frequency reconstruction (HFR), as well as to digital effect processors, e.g. exciters, where generation of harmonic distortion add brightness to the processed signal, and to time stretchers where a signal duration is prolonged with maintained spectral content. A system and method configured to generate a time stretched and/or frequency transposed signal from an input signal is described. The system comprises an analysis filterbank configured to provide an analysis subband signal from the input signal; wherein the analysis subband signal comprises a plurality of complex valued analysis samples, each having a phase and a magnitude. Furthermore, the system comprises a subband processing unit configured to determine a synthesis subband signal from the analysis subband signal using a subband transposition factor Q and a subband stretch factor S.
    Type: Application
    Filed: September 19, 2018
    Publication date: January 17, 2019
    Applicant: Dolby International AB
    Inventor: Lars Villemoes
  • Publication number: 20190013034
    Abstract: The present document relates to audio source coding systems. In particular, the present document relates to audio source coding systems which make use of linear prediction in combination with a filterbank. A method for estimating a first sample (615) of a first subband signal in a first subband of an audio signal is described. The first subband signal of the audio signal is determined using an analysis filterbank (612) comprising a plurality of analysis filters which provide a plurality of subband signals in a plurality of subbands from the audio signal, respectively.
    Type: Application
    Filed: September 12, 2018
    Publication date: January 10, 2019
    Applicant: DOLBY INTERNATIONAL AB
    Inventor: Lars VILLEMOES
  • Patent number: 10170125
    Abstract: An audio decoding system (100) for processing a two-channel input signal (X) comprises a parametric mixing stage (110). The parametric mixing stage receives the two-channel input signal and a set of mixing parameters (P1), and outputs a two-channel output signal (Y1). The parametric mixing stage comprises a decorrelation stage (111) outputting a decorrelated signal (D1) based on the input signal. The parametric mixing stage further comprises a mixing matrix (112) receiving the input signal and the de-correlated signal, and forming a two-channel linear combination of channels from the input signal and the decorrelated signal. The mixing matrix outputs the linear combination as the two-channel output signal. Coefficients of the linear combination are controllable by the set of mixing parameters, and at least four mixing parameters of the set are independently assignable.
    Type: Grant
    Filed: September 8, 2014
    Date of Patent: January 1, 2019
    Assignee: Dolby International AB
    Inventors: Lars Villemoes, Leif Jonas Samuelsson, Kristofer Kjoerling, Heiko Purnhagen, Leif Sehlstrom
  • Patent number: 10163446
    Abstract: This disclosure falls into the field of audio coding, in particular it is related to the field of spatial audio coding, where the audio information is represented by multiple audio objects including at least one dialog object. In particular the disclosure provides a method and apparatus for enhancing dialog in a decoder in an audio system. Furthermore, this disclosure provides a method and apparatus for encoding such audio objects for allowing dialog to be enhanced by the decoder in the audio system.
    Type: Grant
    Filed: October 1, 2015
    Date of Patent: December 25, 2018
    Assignee: Dolby International AB
    Inventors: Jeroen Koppens, Lars Villemoes, Toni Hirvonen, Kristofer Kjoerling
  • Publication number: 20180366130
    Abstract: An apparatus for processing an input audio signal relies on a cascade of filterbanks, the cascade having a synthesis filterbank for synthesizing an audio intermediate signal from the input audio signal, the input audio signal being represented by a plurality of first subband signals generated by an analysis filterbank, wherein a number of filterbank channels of the synthesis filterbank is smaller than a number of channels of the analysis filterbank. The apparatus furthermore has a further analysis filterbank for generating a plurality of second subband signals from the audio intermediate signal, wherein the further analysis filterbank has a number of channels being different from the number of channels of the synthesis filterbank, so that a sampling rate of a subband signal of the plurality of second subband signals is different from a sampling rate of a first subband signal of the plurality of first subband signals.
    Type: Application
    Filed: June 22, 2018
    Publication date: December 20, 2018
    Inventors: Lars VILLEMOES, Per EKSTRAND, Sascha DISCH, Frederik NAGEL, Stephan WILDE
  • Patent number: 10157623
    Abstract: The present invention proposes a new method for improving the performance of a real-valued filterbank based spectral envelope adjuster. By adaptively locking the gain values for adjacent channels dependent on the sign of the channels, as defined in the application, reduced aliasing is achieved. Furthermore, the grouping of the channels during gain-calculation, gives an improved energy estimate of the real valued subband signals in the filterbank.
    Type: Grant
    Filed: December 1, 2017
    Date of Patent: December 18, 2018
    Assignee: Dolby International AB
    Inventors: Kristofer Kjoerling, Lars Villemoes
  • Patent number: 10134413
    Abstract: Embodiments relate to an audio processing unit that includes a buffer, bitstream payload deformatter, and a decoding subsystem. The buffer stores at least one block of an encoded audio bitstream. The block includes a fill element that begins with an identifier followed by fill data. The fill data includes at least one flag identifying whether enhanced spectral band replication (eSBR) processing is to be performed on audio content of the block. A corresponding method for decoding an encoded audio bitstream is also provided.
    Type: Grant
    Filed: March 10, 2016
    Date of Patent: November 20, 2018
    Assignee: Dolby International AB
    Inventors: Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Patent number: 10129645
    Abstract: A method performed by an audio decoder for reconstructing N audio channels from an audio signal containing M audio channels is disclosed. The method includes receiving a bitstream containing an encoded audio signal having M audio channels and a set of spatial parameters, the set of spatial parameters including an inter-channel intensity difference parameter and an inter-channel coherence parameter. The encoded audio bitstream is then decoded to obtain a decoded frequency domain representation of the M audio channels, and at least a portion of the frequency domain representation is decorrelated with an all-pass filter having a fractional delay. The all-pass filter is attenuated at locations of a transient. A matrixed version of the decorrelated signals are summed with a matrixed version of the decoded frequency domain representation to obtain N audio signals that collectively having N audio channels where M is less than N.
    Type: Grant
    Filed: April 26, 2017
    Date of Patent: November 13, 2018
    Assignee: Dolby International AB
    Inventors: Heiko Purnhagen, Lars Villemoes, Jonas Engdegard, Jonas Roeden, Kristofer Kjoerling
  • Publication number: 20180322886
    Abstract: The present document relates an audio encoding and decoding system (referred to as an audio codec system). In particular, the present document relates to a audio codec system which is particularly well suited for voice encoding/decoding. A transform-based speech encoder is configured to encode a speech signal into a bitstream is described. A speech decoder configured to decode audio signals from a bitstream is further described.
    Type: Application
    Filed: July 11, 2018
    Publication date: November 8, 2018
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Lars VILLEMOES, Janusz KLEJSA, Per HEDELIN
  • Publication number: 20180322889
    Abstract: Embodiments relate to an audio processing unit that includes a buffer, bitstream payload deformatter, and a decoding subsystem. The buffer stores at least one block of an encoded audio bitstream. The block includes a fill element that begins with an identifier followed by fill data. The fill data includes at least one flag identifying whether enhanced spectral band replication (eSBR) processing is to be performed on audio content of the block. A corresponding method for decoding an encoded audio bitstream is also provided.
    Type: Application
    Filed: July 19, 2018
    Publication date: November 8, 2018
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Patent number: 10123146
    Abstract: A multi-channel decoder for generating a binaural signal from a downmix signal using upmix rule information on an energy-error introducing upmix rule for calculating a gain factor based on the upmix rule information and characteristics of head related transfer function based filters corresponding to upmix channels. The one or more gain factors are used by a filter processor for filtering the downmix signal so that an energy corrected binaural signal having a left binaural channel and a right binaural channel is obtained.
    Type: Grant
    Filed: December 15, 2017
    Date of Patent: November 6, 2018
    Assignee: Dolby International AB
    Inventor: Lars Villemoes
  • Publication number: 20180315434
    Abstract: The present invention relates to transposing signals in time and/or frequency and in particular to coding of audio signals. More particular, the present invention relates to high frequency reconstruction (HFR) methods including a frequency domain harmonic transposer. A method and system for generating a transposed output signal from an input signal using a transposition factor T is described. The system comprises an analysis window of length La, extracting a frame of the input signal, and an analysis transformation unit of order M transforming the samples into M complex coefficients. M is a function of the transposition factor T. The system further comprises a nonlinear processing unit altering the phase of the complex coefficients by using the transposition factor T, a synthesis transformation unit of order M transforming the altered coefficients into M altered samples, and a synthesis window of length Ls, generating a frame of the output signal.
    Type: Application
    Filed: July 5, 2018
    Publication date: November 1, 2018
    Applicant: Dolby International AB
    Inventors: Per Ekstrand, Lars Villemoes
  • Patent number: 10115405
    Abstract: The present invention proposes a new method for improving the performance of a real-valued filterbank based spectral envelope adjuster. By adaptively locking the gain values for adjacent channels dependent on the sign of the channels, as defined in the application, reduced aliasing is achieved. Furthermore, the grouping of the channels during gain-calculation, gives an improved energy estimate of the real valued subband signals in the filterbank.
    Type: Grant
    Filed: October 31, 2017
    Date of Patent: October 30, 2018
    Assignee: Dolby International AB
    Inventors: Kristofer Kjoerling, Lars Villemoes
  • Patent number: 10109296
    Abstract: The present document relates to audio source coding systems which make use of a harmonic transposition method for high frequency reconstruction (HFR), as well as to digital effect processors, e.g. exciters, where generation of harmonic distortion add brightness to the processed signal, and to time stretchers where a signal duration is prolonged with maintained spectral content. A system and method configured to generate a time stretched and/or frequency transposed signal from an input signal is described. The system comprises an analysis filterbank configured to provide an analysis subband signal from the input signal; wherein the analysis subband signal comprises a plurality of complex valued analysis samples, each having a phase and a magnitude. Furthermore, the system comprises a subband processing unit configured to determine a synthesis subband signal from the analysis subband signal using a subband transposition factor Q and a subband stretch factor S.
    Type: Grant
    Filed: November 27, 2017
    Date of Patent: October 23, 2018
    Assignee: Dolby International AB
    Inventor: Lars Villemoes